Introduction to Porous Materials

Pascal Van Der Voort, Karen Leus, Els De Canck

• Publisher: Wiley
• Year: 2019
• ISBN:
  9781119426707
• Edition: 1
• Topic: Sciences physiques
• Subtopic: Chimie inorganique

The first comprehensive textbook on the timely and rapidly developing topic of inorganic porous materials

This is the first textbook to completely cover a broad range of inorganic porous materials. It introduces the reader to the development of functional porous inorganic materials, from the synthetic zeolites in the 50's, to today's hybrid materials such as metal-organic frameworks (MOFs), covalent organic frameworks (COFs) and related networks. It also provides the necessary background to understand how porous materials are organized, characterized, and applied in adsorption, catalysis, and many other domains. Additionally, the book explains characterization and application from the materials scientist viewpoint, giving the reader a practical approach on the characterization and application of the respective materials.

Introduction to Inorganic Porous Materials begins by describing the basic concepts of porosity and the different types of pores, surfaces, and amorphous versus crystalline materials, before introducing readers to nature's porous materials. It then goes on to cover everything from adsorption and catalysis to amorphous materials such as silica to inorganic carbons and Periodic Mesoporous Organosilicas (PMOs). It discusses the synthesis and applications of MOFs and the broad family of COFs. It concludes with a look at future prospects and emerging trends in the field.

• The only complete book of its kind to cover the wide variety of inorganic and hybrid porous materials
• A comprehensive reference and outstanding tool for any course on inorganic porous materials, heterogeneous catalysis, and adsorption
• Gives students and investigators the opportunity to learn about porous materials, how to characterize them, and understand how they can be applied in different fields

Introduction to Inorganic Porous Materials is an excellent book for students and professionals of inorganic chemistry and materials science with an interest in porous materials, functional inorganic materials, heterogeneous catalysis and adsorption, and solid state characterization techniques.

1
Nature's Porous Materials: From Beautiful to Practical

Porous materials are materials that contain voids, channels, holes, or basically pores. This type of material has always attracted a lot of attention as the presence of pores means that the material possesses an internal surface area of interest for all type of applications (see Chapter 2). Nowadays, many porous materials are made in the laboratory and can even be produced on a large industrial scale (see Chapters 3 and 4). However, many porous materials are naturally occurring and were first produced in “Nature's laboratory” without any human influence. In fact, mankind has often based the preparation procedures of synthetically porous materials on processes that occur in nature.

Nature has found a way to produce beautiful and practical porous materials and they can be very diverse: tissue or bones in the human body and animals, rocks, fruit, and so on. A general overview with some examples is presented in Figure 1.1. Besides that, mankind has found its own way to introduce porosity in many materials as some examples clearly demonstrate (Figure 1.2). Ceramics, bricks, and clothing are a few items that were developed very early.

Figure 1.1 Examples of naturally occurring porous materials: lemons, snowflakes, sea sponges, coral reef, egg shells, butterfly wings (European peacock butterfly), soil, and sandstones.

Source: All photographs are public domain.

Figure 1.2 Synthetic porous materials, all made by mankind: Concrete road, paper, fabric of clothes, chalk, ceramics, cake, bread, pottery, bricks, and artificial sponges for cleaning.

Source: All photographs are public domain.

This chapter describes a few carefully selected naturally occurring porous materials. It aims to give the reader a taste of what is available in nature. These materials are also the foundation for development of synthetic porous materials that are more elaborately described in Chapters 3–9 of this book. Silicas and zeolites are also materials that were originally found in nature before a synthetic procedure was discovered to produce them. They will not be covered in this chapter, as they are described in depth in Chapters 3 and 4.

1.1 Living Porosity

1.1.1 Butterflies

Porous materials can be found in animal and human bodies. The bones and lungs of humans are famous examples of ingenious porous structures. In particular, the bones of a human skeleton are very robust, despite their high porosity, as they must support and protect our body and vital organs, respectively. Animals can also create porous structures of very diverse and beautiful shapes. For example, sponges are multicellular organisms that have an entire body containing pores. The wings of butterflies are not only colorful and useful to fly, but they are also porous (Figure 1.3). The cuticle on the scales of these butterflies' wings is composed of nano‐ and microscale, transparent, chitin‐and‐air layered structures. Rather than absorb and reflect certain light wavelengths as pigments and dyes do, these multiscale structures cause light that hits the surface of the wing to diffract and interfere. Cross ribs that protrude from the sides of ridges on the wing scale diffract incoming light waves, causing the waves to spread as they travel through spaces between the structures. The diffracted light waves then interfere with each other so that certain color wavelengths cancel out (destructive interference) while others are intensified and reflected (constructive interference). The varying heights of the wing scale ridges appear to affect the interference such that the reflected colors are uniform when viewed from a wide range of angles.

Figure 1.3 (a) Optical image of M. menelaus; (b,c) Scanning Electron Microscope (SEM) image of the nanostructure of the wing under different magnification. (d) Optical image of P. u. telegonus; (e) SEM image of the nanostructure of the blue region; the insert in (e) is the high magnification of SEM image; (f) SEM image of the nanostructure of the fiber region; and, the insert in (f) is th...